1. Field of Invention
This invention relates to the art of mineral beneficiation of phosphorous containing materials. More specifically, the invention relates to the removal of apatite from phosphatic materials having a particle size less than 0.25 millimeter (hereinafter mm).
2. Background of the Invention
Sediments mined in Florida for phosphate ore contain approximately one third ore (apatite) [Ca.sub.5 (F or Cl) (PO.sub.4).sub.3 ], one third quartz, and one third clay. Apatite is a relatively insoluble material. The usual order of abundance of clay species is: smectite, palygorskite, illite and kaolin.
The +105 micrometer (hereinafter .mu.m) size ore is separated from sand and clay by wet sieving and flotation procedures. The -105 .mu.m fraction is waste clay containing up to 30% of the total phosphorous that was present in the original sediment. At present this phosphorous is lost through disposal of the waste clay slurry.
Such a loss of raw materials containing phosphorous is costly. This invention reduces this waste. Such a process also diminishes the waste associated with phosphorous mining and promotes the conservation of natural resources.